Corduroy fabrics generally have a greater thickness and a desirable warm-keeping characteristic, thus are suitable for making autumn and winter overcoats, and ornamental articles such as outer layers of shoes and hats, draperies, curtains, surface fabrics of sofas, and the like. There are many types of corduroy fabrics. Depending on the size of pile strips, they can be divided into extra fine strip, fine strip, medium strip, coarse strip, and broad strip. Other types also are available, such as with coarse strips and fine strips spaced alternatively, without cutting piles on a portion of the strips, or having the piles cut in a bias manner to form alternative heights on the strips, or the like. In general, the corduroy fabric is formed by weaving medium yarns. The ground fabric can adopt plain weave, twill weave, altered weft plain weave or the like.
The conventional corduroy fabric is fabricated by shuttle weaving. The fabric consists of one set of warp yarns and two sets of weft yarns woven manually or through semi-automatic machines. Referring to FIGS. 1A and 1B for a conventional V-shaped corduroy fabric fabricated by shuttle weaving with the pile yarns cut in a V-shape. It has a ground fabric formed by weaving one set of weft yarns (or called ground wefts 11 and 12) and warp yarns 21 and 22 to fasten piles, and another set of weft yarns (or called pile wefts 911 and 912) and the warp yarns 21 and 22 woven to form regular float wefts 971 and 972. The float wefts 971 and 972 are cut to form V-shaped piles 921 and 922. Then the pile wefts 911 and 912 are cut and the V-shaped piles 921 and 922 direct upwards in V-shape. Hence the fabric surface forms a plurality of longitudinal pile strips 2912 which have a cross section like lamp wicks to become a corduroy fabric.
The fabric shown in FIG. 1A adopts a 1:2 plain weaving ground. The ground fabric is formed by weaving consecutively two pile wefts 911 and 912 for every woven ground weft 11, and the warp yarns 21 and 22, and the ground wefts 11 and 12 are woven to form the ground fabric so that the pile wefts 911 and 912 have a regular length (generally at a length of 5-6 warp yarns) floating on the fabric surface. Referring to FIG. 1B, after the pile wefts 911 and 912 have been cut, the piles 921 and 922 are formed in a V-shape and fastened by the ground fabric (formed by the warp yarns 21, 22, and weft yarns 11 and 12). As the V-shaped piles 921 and 922 are fastened to the ground fabric at a few cross weaving spots formed by the warp yarns 21 and 22, the V-shaped piles 921 and 922 are easily loosened off. Hence such a weaving method is generally adoptable to a broad strip corduroy fabric with a high weft density. Ii usually is woven manually or through semi-automatic machines. As a result, production efficiency is lower.
Refer to FIG. 2 for another type of conventional corduroy fabric with a W-shaped pile structure. It also adopts a 1:2 plain weaving ground. It has a ground fabric formed by weaving one weft yarn 13 and two consecutive pile wefts 23 and 24 (no mark in the drawing), and weaving warp yarns 23, 24, 25 and 26 and ground wefts 13 and 14 so that the pile weft has a regular length (generally at a length of 4-5 warp yarns) floating on the fabric surface. After cut, the pile wefts form W-shaped piles 981 and 982 clipped by the ground fabric (formed by the warp yarns 23, 24, 25 and 26, and the ground wefts 13 and 14). The W-shaped piles 981 and 982 and the warp yarns are woven with a greater number of crossed spots, thus can form a more secured fastening than the V-shaped piles. It generally is suitable for fabricating medium strip or fine strip corduroy fabrics. But fabricated by the conventional shuttle weaving, the resulting W-shaped piles 981 and 982 still could loosen off, and production efficiency still is not desirable.
In short, the conventional corduroy fabrics fabricated by shuttle weaving, either with V-shaped or W-shaped piles, still have common problems remained to be overcome, notably:
1. the piles easily loosen off; and
2. production efficiency is too low.